The present invention relates to cable protectors for tubulars.
It is known to protect or support cables as they pass along the outside of tubing strings and other tubulars in a downhole well. For example, generally cylindrical cable protectors have been applied across couplings in a tubing string and have been provided with cable slots to receive, and thereby protect, cables.
The invention seeks to extend this concept and to provide protection for cables at other locations.
According to a first aspect of the present invention there is provided a cable protector for tubulars, the cable protector comprising an elongate protector body having a substantially circular internal cross-section, the protector body being formed by two or more body members hingedly connected to enable the protector body to encircle a tubular, the protector body further comprising fastening means for fastening body members together to hold the protector body around the tubular, and the protector body further comprising a cable slot extending longitudinally of the protector body along an inner surface thereof, and wherein the internal transverse dimension of the protector body varies along the length thereof whereby cables received within the cable slot are constrained to follow a path along the cable protector which has a varying spacing from the longitudinal axis of the cable protector.
In an embodiment, the internal transverse dimension of the protector body is less at one end thereof than at the other end thereof.
A subsea safety valve, for example, has an outside diameter which is considerably larger than that of the tubing string in which the safety valve is incorporated. This provides a varying diameter along the length of the tubular, and a cable protector of the invention may be used to guide and protect cables which span the safety valve.
In this respect, the term xe2x80x9ccablexe2x80x9d is used herein to refer to any cable, wire, or similar elongate item which extends along the outside of a tubular.
In an embodiment, one or more cable retention members are received within the cable slot to retain cables therein.
The provision of cable retention members ensures that the cable or cables are fully captivated within the cable protector. This increases the protection and support for the cables and ensures that the cable or cables cannot be inadvertently removed.
The present invention also extends to a cable protector for tubulars, the cable protector comprising an elongate protector body having a substantially circular internal cross-section, the protector body being formed by two or more body members hingedly connected to enable the protector body to encircle a tubular, the protector body further comprising fastening means for fastening body members together to hold the protector body around the tubular, and the protector body further comprising a cable slot extending longitudinally of the protector body along an inner surface thereof, and wherein one or more cable retention members are receivable within said cable slot to retain cables therein.
In an embodiment, the internal transverse dimension of the protector body varies along the length thereof whereby cables received within the cable slot are constrained to follow a path along the cable protector which has a varying spacing from the longitudinal axis of the cable protector.
For example, the internal transverse dimension of the protector body may be less at one end thereof than at the other end whereby cables retained within the cable slot span an area along a tubular with a varying diameter.
In one embodiment, the elongate protector body of the cable protector is formed by two cooperating body members hingedly connected along an elongate hinge line.
The hinge may be formed by any appropriate means. In a preferred embodiment, two or more individual hinge pins are spaced along the hinge line to connect the two body members together.
The body members may be made of any appropriate materials and may be shaped appropriately. In one embodiment, each of the two body members is cast from metal, and may be substantially solid, or may be cast to have areas omitted to save material and weight. In this latter case, the resulting protector body may, although formed from only two body members, be configured to present two annular collars interconnected by elongate blades.
In an alternative construction, the cable protector is formed from three cooperating body members. The first body member is a base member which is substantially semicircular in configuration, and at each of its ends second body members in the form of collars are hingedly connected thereto whereby the resultant cable protector has two annular collars interconnected by the semicircular base body member.
The base member may be substantially solid, and, for example, cast from metal. Alternatively, the base member may be configured to have spaced end collars interconnected by elongate blades.
There are various configurations of cable protectors in use, and any of these known configurations may be adapted for use in an embodiment of the present invention.
Where two collars are hingedly connected to a base member, each collar is preferably hingedly connected to the base member to define an elongate hinge line. For example, each collar is hinged to the base member by way of a respective hinge pin.
Fastening means are provided for fastening the body members together. For example, two body members may be held together by two spaced fastening members. Where the construction utilises spaced collars, each collar may be fastened to the base member by a respective fastening means.
It is preferred that the fastening means be configured such that they do not protrude relative to the external surface of the cable protector.
In a preferred embodiment, each fastening means comprises a fastening member appropriately mounted in the material of a body member or collar and pivotable relative to that body member or collar to enable fastening thereof. The use of a pivotable fastening member is particularly preferred as pivoting movement can be prevented if the fastening member is in an incorrect position. This means that if a fastening member is moved by vibration or other downhole conditions, inadvertent unfastening is prevented.
In a preferred embodiment, each fastening member is an elongate bolt pivotally mounted with respect to a body member of the cable protector. A nut or other fastening means is threaded onto the bolt and is arranged to engage a further body member whereby the two body members are fastened together.
In a preferred embodiment, the bolt of each fastening member extends through a tubular barrel which provides the pivoting movement of the fastening member.